Water-cooled air conditioner and method of controlling the same

ABSTRACT

A water-cooled air conditioner and a method controlling the same are provided. The water-cooled air conditioner includes a compressor for compressing refrigerant, a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat exchanged with water, water inflow and outflow pipes for guiding inflow and outflow of the water, and a water detecting unit for detecting if the water exists in the heat exchanger. The water inflow and outflow pipes are provided in the heat exchanger. The water detecting unit is provided at a side of one of the water inflow and outflow pipes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a water-cooled air conditioner, and more particularly, to an air conditioner having a water-cooled heat exchanger for allowing a refrigerant to be heat-exchanged with water and a detecting unit for detecting if water is in existence or if water flows in the water-cooled heat exchanger. The present invention further relates to a method of controlling the water-cooled air conditioner.

2. Description of the Related Art

Generally, an air conditioner is designed to reduce a temperature of an indoor space by (a) sucking warm indoor air, (b) heat-exchanging the warm indoor air with refrigerant, and (c) discharging the heat-exchanged air to the indoor space or to increase the temperature of the indoor space through a reverse cycle. The air conditioner provides a cooling/heating cycle in which the refrigerant circulates through a compressor, a condenser, and expansion valve, and an evaporator in this order.

Recently, as the quality of the life is improved and in response to the needs of the customers, in addition to the air cooling/heating function, the air conditioner also provides a variety of other functions such as an air cleaning function for discharging purified air into the indoor space after filtering off foreign objects contained in sucked air or a dehumidifying function for discharging dry air into the indoor space after changing humid sucked air into the dry air.

Meanwhile, the air conditioner is generally divided into an outdoor unit (called a heat discharge unit) installed at an outdoor space and an indoor unit (called a heat absorption unit) installed at an indoor space. The outdoor unit includes a condenser (a second heat exchanger) and a compressor and the indoor unit includes an evaporator (a first heat exchanger).

The air conditioner is generally classified into a split type air conditioner where the outdoor and indoor units are separately installed and an integral type air conditioner where the outdoor and indoor units are integrally installed. The split type air conditioner has been widely used due to its advantages in terms of an installation space and noise.

In order to reduce excessive power consumption during the air-conditioning of the indoor air, a water-cooled air conditioner has been actively used and developed.

Unlike a condenser (a second heat exchanger) of a conventional air-cooled air conditioner where the refrigerant is cooled by an outdoor air, the refrigerant of the water-cooled air conditioner is cooled by water. That is, the water and the refrigerant are not mixed with each other but separately pass through a second heat exchanger.

In the water-cooled air conditioner, as the water and the refrigerant separately flow along the water-cooled condenser (the second heat exchanger) without being mixed with each other, the water and the refrigerant are heat-exchanged with each other.

When the refrigerant and the water separately flow through the water-cooled condenser (second heat exchanger), the heat-exchange between the refrigerant and the water occurs in the water-cooled condenser.

In the conventional water-cooled condenser (the second heat exchanger), no unit for detecting if the water exists and flows is provided. Therefore, when no water is in the air conditioner, the air-conditioning cannot be realized. This deteriorates the reliability of the products.

Furthermore, when the water freezes or leaks, this causes the damage of the water-cooled condenser and thus the increase of the maintenance costs.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a water-cooled air conditioner and a method of controlling the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a water-cooled air conditioner having a water level detecting unit for detecting if water exists in a heat exchanger through which refrigerant and water circulate to be heat-exchanged with each other.

Another object of the present invention is to provide a water-cooled air conditioner having a water flow detecting unit for detecting whether the water flows in a heat exchanger through which refrigerant and water circulate to be heat-exchanged with each other.

Still another object of the present invention is to provide a method of controlling a water-cooled air conditioner, which can prevent a damage of a heat exchanger by detecting if water exists in the heat exchanger and detecting if water flows in the heat exchanger using a water level detecting unit and a water flow detecting unit.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a water-cooled air conditioner including: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; and a water detecting unit for detecting if the water exists in the heat exchanger, the water detecting unit being provided at a side of one of the water inflow and outflow pipes.

In another aspect of the present invention, there is provided a water-cooled air conditioner including: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; and a water flow detecting unit for detecting if the water flows in the heat exchanger, the water flow detecting unit being provided at a side of one of the water inflow and outflow pipes.

In still another aspect of the present invention, there is provided a water-cooled air conditioner including: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; a water detecting unit for detecting if the water exists in the heat exchanger, the water detecting unit being provided at a side of one of the water inflow and outflow pipes; and a water flow detecting unit for detecting if the water flows in the heat exchanger, the water flow detecting unit being provided at a side of one of the water inflow and outflow pipes.

In still yet another aspect of the present invention, there is provided a method of controlling a water-cooled air conditioner, including: detecting a water level of one of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing the water level detected with a reference water level; and controlling a driving of a compressor depending on a comparison result between the detected water level and the reference water level.

In still yet another aspect of the present invention, there is provided a method of controlling a water-cooled air conditioner, including: detecting water pressures of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing a pressure difference between the water pressures detected with a reference water pressure; and controlling a driving of a compressor depending on a comparison result between the pressure difference and the reference water pressure.

In still yet another aspect of the present invention, there is provided a method of controlling a water-cooled air conditioner, including: detecting water temperatures of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing a temperature difference between the water temperatures detected with a reference water temperature; and controlling a driving of a compressor depending on a comparison result between the temperature difference and the reference water temperature.

In further still yet another aspect of the present invention, there is provided a method of controlling a water-cooled air conditioner, including: detecting a water level of one of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing the water level detected with a reference water level; controlling a driving of a compressor depending on a comparison result between the detected water level and the reference water level; detecting if the water flows in the heat exchanger using a water flow detecting unit provided at a side of the heat exchanger; and further controlling the driving of the compressor depending on whether the water flows or not.

According to the above-defined water-cooled air conditioner, the water level detecting unit for detecting if water exists in the second heat exchanger in which the refrigerant and the water circulate to be heat-exchanged with each other is provided on a side of the second heat exchanger. That is, a float switch is used as the water level detecting unit to measure a water level, thereby detecting if the water exists or not. Therefore, the overheating of the second heat exchanger, which may be caused when no water exists or a water level is lower than a predetermined level, can be prevented.

In addition, according to the above-described water-cooled air conditioner, the water flow detecting unit for detecting if water flows in the second heat exchanger in which the refrigerant and the water circulate to be heat-exchanged with each other is provided on a side of the second heat exchanger. That is, a water temperature sensor and a water pressure sensor are provided as the water flow detecting unit to detect if the water flows or not. Therefore, the user can identify if there is a foreign object is in the second heat exchanger or if the water is frozen and thus prevent the air conditioner from getting out of order in advance.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is an air view illustrating a state where a water-cooled air conditioner according to an embodiment of the present invention is installed in a building;

FIG. 2 is a view illustrating flows of air and water in a building when an integral type water-cooled air conditioner according to an embodiment of the present invention operates;

FIG. 3 is an air view illustrating a state where a multiple water-cooled air conditioner according to another embodiment of the present invention is installed in a building;

FIG. 4 is a perspective view of an outdoor unit of a water-cooled air conditioner according to an embodiment of the present invention;

FIG. 5 is an exploded perspective view of an internal structure of the outdoor unit of FIG. 4;

FIG. 6 is a view illustrating flows of refrigerant and water during an air cooling operation of a water-cooled air conditioner according to an embodiment of the present invention;

FIG. 7 is an enlarged view illustrating a floater switch of a water-cooled air conditioner according to an embodiment of the present invention;

FIG. 8 is a block diagram of a method for controlling a water-cooled air conditioner using a floater switch according to an embodiment of the present invention;

FIG. 9 is a block diagram of a method for controlling a water-cooled air conditioner using a water pressure sensor according to an embodiment of the present invention;

FIG. 10 is a block diagram of a method for controlling a water-cooled air conditioner using a water temperature sensor according to an embodiment of the present invention;

FIG. 11 is a block diagram of a method for controlling a water-cooled air conditioner using both of a floater switch and a flow detecting unit according to an embodiment of the present invention; and

FIG. 12 is a schematic view illustrating flows of refrigerant and water during a heating mode operation of a water-cooled air conditioner according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

FIG. 1 shows an air view illustrating a state where a water-cooled air conditioner according to an embodiment of the present invention is installed in a building, and FIG. 2 is a view illustrating flows of air and water in a building when an integral type water-cooled air conditioner according to an embodiment of the present invention operates.

Referring to FIGS. 1 and 2, a water-cooled air conditioner is installed in an enclosed space 52 formed in a building 50. The enclosed space 52 is completely isolated from an external side of the building 50 and communicates with an indoor space 62 through an air intake 60 formed through a ceiling to suck indoor air.

A duct 70 is connected to the indoor space 62 to allow air heat-exchanged by the water-cooled air conditioner to be discharged into the indoor space 62. That is, the water-cooled air conditioner includes an indoor unit 100 for sucking the indoor air and discharging the indoor air after heat-exchanging the indoor air and an outdoor air 200 connected to the indoor unit 100 by a refrigerant pipe (130 of FIG. 3) and allowing the refrigerant introduced through the refrigerant pipe to be heat-exchanged with a water. The duct 70 allows the indoor unit 100 to communicate with the indoor space 62.

The outdoor unit 200 includes a compressor 210, an accumulator (270 of FIG. 5), a second heat exchanger 290, and an outdoor linear expansion valve (234 of FIG. 6). The indoor unit 100 includes a first heat exchanger 120 and an expansion valve (not shown).

When the water-cooled air conditioner operates, the indoor air is introduced into the indoor unit 100 through the air intake 60 formed in the ceiling of the building. For this indoor air circulation, an indoor fan 110 for making an indoor air current is installed in the indoor unit 100. In addition, the first heat exchanger 120 is installed to be inclined at a lower side of the indoor fan 110.

The first heat exchanger 120 is provided to heat-exchange the indoor air using the refrigerant flowing inside the first heat exchanger 120. The first heat exchanger 120 is connected to the second heat exchanger 290 by the refrigerant pipe 130.

The refrigerant pipe 130 is designed to circulate the refrigerant between the indoor and outdoor units 100 and 200. A common liquid pipe (132 of FIG. 6) along which a liquid-phase refrigerant flows and which is a single pipe and a common gas pipe (134 of FIG. 6) along which a gas-phase refrigerant flows and which is a single pipe are provided between the indoor and outdoor units 100 and 200.

That is, the common liquid pipe 132 connects the second heat exchanger 290 to the first heat exchanger 120 and the common gas pipe 134 connects the compressor 210 to the first heat exchanger 120.

Although the installing location of the indoor unit 100 may vary depending on a type of the water-cooled air conditioner (integral type or split type), an internal structure thereof is almost identical to that of a conventional indoor unit. Therefore, a detailed description of the indoor unit 100 will be omitted herein.

The outdoor unit 200 is provided under the indoor unit 100. The compressor 210 of the outdoor unit 200 compresses the refrigerant with a high temperature and a high pressure. The second heat exchanger 290 of the outdoor unit 200 allows the refrigerant introduced from the compressor 210 to be heat-exchanged with water directed from a cooling tower 80 installed on, for example, a building 50 top. The second heat exchanger 290 is provided with a waterway 202 communicating with an inside of the cooling tower 80. The waterway 202 includes a water inflow passage 202′ for directing the water from the cooling tower 80 to the second heat exchanger 290 and a water outflow passage 202″ for directing the water, which is heat-exchanged with the refrigerant while passing through an inside of the second heat exchanger 290, into the cooling tower 80.

The following will describe a case where a multiple water-cooled air conditioner is applied with reference to FIG. 3. FIG. 3 is an air view illustrating a state where a multiple water-cooled air conditioner according to another embodiment of the present invention is installed in a building.

As shown in FIG. 3, when the water-cooled air conditioner is provided as a multiple type, the indoor and outdoor units 100 and 200 are separated from each other and connected by a refrigerant pipe 130. That is, the indoor unit 100 is installed on the ceiling of the indoor space 62, and the outdoor unit 200 is installed in the enclosed space 52. The indoor and outdoor units 100 and 200 are connected to each other by the refrigerant pipe 130 so that the refrigerant can circulate and allow the indoor air to be heat-exchanged.

A first heat exchanger (not shown) by which the indoor air is heat-exchanged with the refrigerant is provided in the indoor unit 100. An indoor fan 110 is further provided to allow the heat-exchanged air to be discharged into the indoor space 62.

Like the integral type water-cooled air conditioner, the multiple water-cooled air conditioner includes a second heat exchanger for allowing the refrigerant to be heat-exchanged with the water. Since the circulations of the refrigerant and water in the second heat exchanger is identically realized to the integral type water-cooled air conditioner, a detailed description thereof will be omitted herein.

The following will describe the outdoor unit 200 of the multiple water-cooled air conditioner by way of example.

FIG. 4 is a perspective view of an outdoor unit of a water-cooled air conditioner according to an embodiment of the present invention, FIG. 5 is an exploded perspective view of an internal structure of the outdoor unit of FIG. 4, and FIG. 6 is a view illustrating flows of refrigerant and water during an air cooling operation of a water-cooled air conditioner according to an embodiment of the present invention.

The following will describe the outdoor unit 200 in more detail with reference to the accompanying drawings.

Referring to FIGS. 4 through 6, the outdoor unit 200 includes a top cover 204 formed in a rectangular parallelepiped and dividing the indoor unit 100 and the outdoor unit 200 from each other, front and rear panels 205 and 207 that define respectively front and rear outer appearances, side panels 208 that define left and right outer appearances, and a base pan 209 for supporting a plurality of components.

The top cover 204 is located at a top of the outdoor unit 200 to prevent the air passing through the indoor unit 100 from being introduced into the outdoor unit 200. That is, the top cover 204 is formed in a rectangular plate in which no hole is formed.

The top cover 204 also functions to support the indoor unit 100 provided thereon. Therefore, the top cover 204 is provided at a bottom edge with a reinforcing beam 204′ for reinforcing strength thereof.

The front panel 205 is erected under a front end of the top cover 204. Service panels 206 are formed at a central left side and a lower left/right side of the front panel 205. The service panels 206 are provided to open an internal side of the outdoor unit 200 when a maintenance service is required due to a malfunctioning of a component installed in the outdoor unit 200. Each of the service panels 206 is provided with slits except for one side.

Therefore, the service panels 206 pivot with reference to a side where no slit is formed to allow the internal space of the outdoor unit 200 to communicate with an external side, thereby allowing for the maintenance service.

The side panels 208 contacts rear-left and rear-right ends of the front panel 205. Each of the side panels 208 is provided at an upper portion with a plurality of heat dissipation holes 208′ through which the heat generated by the operation of the compressor is dissipated to the external side.

Although not shown in the drawings, the top cover 204, the front panel 205, the rear panel 207, and the side panel 208 may be provided with connection holes through which the common gas pipe 134 and the common liquid pipe 132 are connected to the indoor unit 100.

The base pan 209 is provided to contact lower ends of the front, rear, and side panels 205, 207, and 208. The base pan 209 is provided to support a plurality of components. Particularly, the compressor 210 is provided on a top center of the base pan 209.

The compressor 210 is designed to compress the refrigerant to a high temperature/pressure state. The compressor 210 is provided at left and right sides. That is, the compressor 210 includes a constant speed compressor 212 operated with a constant speed and installed at a relatively right side and an inverter compressor 214 that is a variable speed heat pump installed at a left side of the constant speed compressor 212 and operated with a variable speed.

A uniform fluid pipe 216 is installed between the constant speed compressor 212 and the inverter compressor 214 to communicate the constant speed compressor 212 and the inverter compressor 214 with each other. Therefore, when one of the compressors 212 and 214 is short of fluid, the fluid of the other is directed to the compressor that is short of the fluid, thereby preventing the compressor 210 from being damaged.

A scroll compressor where noise is not so intrusive may be used as the compressor 210. Particularly, an inverter scroll compressor whose RPM is controlled depending on a load capacity may be used as the inverter compressor 214.

Therefore, when a load applied to the compressor 210 is low, the inverter compressor 214 first operates. Then, as the load capacity applied to the compressor 210 gradually increases and thus the inverter compressor 214 is unequal to the increased load capacity, the constant speed compressor 212 operates.

The compressor 210 is provided at an outlet side with a compressor discharge temperature sensor 217 for detecting a temperature of the refrigerant discharged from the compressor 210 and an oil separator 218. The oil separator 218 filters oil mixed in the refrigerant discharged from the compressor 210 and allows the filtered oil to be returned to the compressor 210.

That is, the oil used for cooling the frictional heat generated during the operation of the compressor 210 is discharged together with the refrigerant through an outlet of the compressor 210. The generated oil is separated in the oil separator 218 and returned to the compressor 210 through the oil recovery pipe 219.

The oil separator 218 is provided at an outlet with a check valve 232 for preventing the refrigerant from flowing back. That is, when only one of the constant speed compressor 212 and the inverter compressor 214 operates, the check valve 232 prevents the refrigerant from flowing into the other of the compressors.

The oil separator 218 is designed to communicate with a four-way valve 240 by a pipe. The four-way valve 240 is provided to convert the flow of the refrigerant according to an operation mode (cooling or heating mode) of the air conditioner. The four-way valve 240 includes an inlet port 242, a first outlet port 244, a second outlet port 246, and a third outlet port 248. The ports are connected to an outlet of the compressor 210 (or the oil separator 218), an inlet of the compressor 210 (or an accumulator 270), the second heat exchanger 290, and the indoor unit 100, respectively.

Therefore, the refrigerant discharged from the inverter compressor 214 and the constant speed compressor 212 is collected in a location and then directed to the four-way valve 240. The four-way valve 240 is provided at an outlet with a high pressure sensor 240′ for detecting the pressure of the refrigerant discharged from the compressor 210.

Meanwhile, a hot gas pipe 250 is installed bypassing the four-way valve 240 to allow a portion of the refrigerant introduced into the four-way valve 240 to be directly directed to the accumulator 270 that will be described in more detail later.

The hot gas pipe 250 is provided to directly direct the high pressure refrigerant of an outlet side of the compressor 210 to the inlet of the hot gas pipe 250 when there is a need to increase the pressure of the low pressure refrigerant introduced into the accumulator 270 during the operation of the air conditioner. A hot gas valve 252 is installed on the hot gas pipe 250 to open and close the hot gas pipe 250.

An over-cooler 260 is installed on a top-right-rear end of the base pan 209. The over-cooler 260 is provided to further cool the refrigerant that is heat-exchanged in the second heat exchanger 290. The over-cooler 260 is formed at a portion of the outdoor liquid pipe 262 connected to the outlet of the second heat exchanger 290.

The over-cooler 260 is formed in a dual-pipe structure. That is, the over-cooler 260 includes an inner pipe communicating with the outdoor liquid-phase pipe 262 and an outer pipe surrounding the inner pipe. A reverse transfer pipe 264 is branched off from the outlet of the over-cooler 260. The reverse transfer pipe 264 is provided with an over-cooler expansion valve 266 for cooling the refrigerant through an expanding process.

Then, a portion of the refrigerant discharged from the over-cooler 260 is introduced into the reverse transfer pipe 264 and cooled while passing through the over-cooler expansion valve 266. The cooled refrigerant flows back through the over-cooler 260 to be further cooled. The backflow refrigerant discharged from the over-cooler 260 is fed again to the accumulator 270 and circulated.

Meanwhile, the over-cooler 260 is provided at an outlet with a liquid pipe temperature sensor 263 for detecting the temperature of the refrigerant discharged from the outdoor unit 200. The over-cooler expansion valve 266 is provided at an outlet with an over-cooler inlet sensor 265 to detect the temperature of the backflow refrigerant inflowing the over-cooler 260. The reverse transfer pipe 264 along which the backflow refrigerant discharged from the over-cooler 260 is provided with an over-cooler outlet sensor 267.

Accordingly, the refrigerant passed through the second heat exchanger 290 flows through a central portion and the low temperature refrigerant expanding by the expansion valve (not shown) flows in an opposite direction at an outer side, thereby further lowering the temperature of the refrigerant.

The accumulator 270 is installed at a left portion of the base pan 209 (i.e., at a left side of the inverter compressor 214). The accumulator 270 functions to filter off the liquid-phase refrigerant and allow only the gas-phase refrigerant to be introduced into the compressor 210.

If the liquid-phase refrigerant that is directed from the indoor unit 100 and is not vaporized is directly introduced into the compressor 210, the compressor 210 for compressing the refrigerant to a high temperature and high pressure gas-phase state is overloaded and thus damaged.

Therefore, since the liquid-phase refrigerant that is introduced into the accumulator 270 and is not vaporized is relatively heavier than the gas-phase refrigerant, the liquid-phase refrigerant is settled down at a lower portion of the accumulator 270 and only the gas-phase refrigerant is introduced into the compressor 210.

The accumulator 270 is provided at an inlet with an intake pipe temperature sensor 272 for detecting the temperature of the refrigerant introduced therein and a low pressure sensor 274.

Meanwhile, a control box 280 is installed in rear of the front panel 205. The control box 280 is formed in a rectangular parallelepiped and is selectively closed by a control cover 282 pivotally fixed on a top end of the control box 280.

Control components such as a voltage transformer, a printed circuit board, and a capacitor are provided in the control box 280 and a heat dissipation unit 284 formed with heat dissipation fins are formed on a rear surface of the control box 280.

The second heat exchanger 290 is provided at a rear side of the control box 280 to allow the refrigerant and the water to be heat-exchanged with each other while passing therethrough. The second heat exchanger 290 is formed in a rectangular parallelepiped.

A plurality of water flow pipes and refrigerant flow pipes are provided in the second heat exchanger 290 to prevent the refrigerant and the water from being mixed with each other. The water and refrigerant flow pipes are alternately arranged to be adjacent to each other so that the heat-exchange between the refrigerant and water can be effectively realized.

That is, the refrigerant flow pipes (not shown) are arranged to surround the water pipes (not shown) while the water pipes are arranged to surround the refrigerant flow pipes. Therefore, it will be preferable that the water and refrigerant pipes are designed to be identical in a sectional shape and size with each other. For example, the water and refrigerant flow pipes are formed in a regular hexagonal shape so that they can be arranged in a honeycomb shape.

The second heat exchanger 290 is provided at a front surface with water inflow and outflow pipes 292 and 293 through which the water is introduced into or discharged from the second heat exchanger 290 and refrigerant inflow and outflow pipes 294 and 295 through which the refrigerant is introduced into or discharged from the second heat exchanger 290.

That is, the water inflow and outflow pipes 292 and 293 are formed on front-right upper and lower portions of the second heat exchanger 290 and extend into the second heat exchanger to guide the introduction and discharge of the water into or from the second heat exchanger 290. The water inflow pipe 292 is positioned under the water outflow pipe 293.

In addition, the refrigerant inflow and outflow pipes 294 and 295 are formed on front-left upper and lower portions of the second heat exchanger 290 and extend into the second heat exchanger 290 to guide the introduction and discharge of the refrigerant into or from the second heat exchanger 290. The refrigerant inlet pipe 294 is positioned under the water outflow pipe 295.

When the water and refrigerant are introduced into the second heat exchanger 290, the water flows from an upper side to a lower side along the water flow pipe disposed in the second heat exchanger 290. The refrigerant introduced into the second heat exchanger 290 flows from the lower side to the upper side along the refrigerant flow pipe.

As the water and the refrigerant flow in an opposite direction to each other in the second heat exchanger 290, the heat exchange efficiency between the water and the refrigerant may be maximized.

Meanwhile, as a feature of the present invention, a water temperature sensor 360 is provided on each of an outer surface of the water outflow pipe 293 and an outer surface of the water inflow pipe 292.

The water temperature sensors 360 are provided to detect the temperature of the water passing through the second heat exchanger 290. The water temperature sensors 360 include an inflow temperature sensor 362 provided on the outer surface of the water inflow pipe 292 and an outflow temperature sensor 364 provided on the outer surface of the water outflow pipe 293.

Therefore, the inflow temperature sensor 362 detects the temperature of the water that is introduced into the second heat exchanger 290 through the water inflow pipe 292. The outflow water temperature sensor 364 detects the temperature of the water that is discharged from the second heat exchanger 290 through the water outflow pipe 293.

The water temperature sensors 360 is designed to selectively stop the operation of the compressor 210 by determining if the water flows in the second heat exchanger 290 depending on the temperatures detected by the inflow and outflow temperature sensors 362 and 364.

That is, the inflow and outflow temperature sensors 362 and 364 are electrically connected to the printed circuit board (not shown) to transmit the detected temperature information to the printed circuit board.

The printed circuit board selectively stops the operation of the compressor 210 by calculating a difference between the temperatures detected by the inflow and outflow temperature sensors 362 and 364 (i.e., subtracts the water temperature of the water inflow pipe 292 from the water temperature of the water outflow pipe 293) and comparing the difference with a reference temperature difference (3° C.).

In more detail, when the water-cooled air conditioner operates with the cooling mode and the temperature difference of the waters passing through the inflow and outflow pipes 292 and 293 is less than 3° C., it is regarded that no heat-exchange occurs between the refrigerant and the water in the second heat exchanger 290. This is regarded as water does not flow and thus the printed circuit board stops the operation of the compressor 210.

When the temperature difference between waters flowing along the inflow and outflow pipes 292 and 293 is less than 3° C., it is determined that the water does not flow in the second heat exchanger 290. That is, when there is a temperature difference between the refrigerant and the water in the second heat exchanger 290, the temperature difference between the water before passing through the second heat exchanger 290 and the water after passing through the second heat exchanger 290 is generally over 3° C.. Therefore, When the temperature difference between the waters flowing along the inflow and outflow pipes 292 and 293 is less than 3° C., it can be determined that the water does not flow in the second heat exchanger 290.

When it is determined that the temperature difference between the waters flowing along the inflow and outflow pipes 292 and 293 is less than 3° C., the printed circuit board transmits a signal to a display (not shown) or a buzzer so as to let the user know that the water does not flow in the second heat exchanger.

A water flow detecting unit that detects if the water flows in the second heat exchanger 290 using a water pressure difference is provided at each side of the inflow and outflow pipes 292 and 293. The water flow detecting unit may be formed in a variety of structures.

In the exemplary embodiment of the present invention, a water pressure sensor 340 and a water temperature sensor 360 are provided as the water flow detecting sensors. However, the present invention is not limited to this case. For example, at least one of the water pressure sensors 340 and the water temperature sensor 360 may be used.

The water pressure sensor 340 is provided to detect a pressure of the water flowing along the inflow and outflow pipes 292 and 293. The water pressure sensor 340 includes an inflow water pressure sensor 342 provided on an outer surface of the inflow pipe 292 and an outflow pressure sensor 344 provided on an outer surface of the outflow pipe 293.

Like the water temperature sensor 360, the water pressure sensor 340 is designed to transmit water pressure data to the printed circuit board. The printed circuit board calculates a pressure difference between the pressures detected by the inflow pressure sensor 342 and the outflow pressure sensor 344 and compares the calculated pressure difference with a reference pressure difference.

That is, the inflow and outflow pressure sensors 342 and 344 are electrically connected to the printed circuit board (not shown) to transmit the detected water pressure data to the printed circuit board.

The printed circuit board selectively stops the operation of the compressor 210 by calculating a water pressure difference between the water pressures detected by the inflow and outflow pressure sensors 342 and 344 (i.e., subtracts the water pressure of the water inflow pipe 292 from the water temperature of the water outflow pipe 293) and comparing the calculated pressure difference with a reference pressure difference (20 kPa).

In more detail, during the cooling mode operation of the water-cooled air conditioner, when the water pressure difference of the waters passing through the inflow and outflow pipes 292 and 293 is over 20 kPa, the printed circuit board stops the operation of the water-cooled air conditioner by determining that the water does not flow due to the foreign objects clogging the second heat exchanger 290. In addition, during the heating mode operation of the water-cooled air conditioner, when the water pressure difference of the waters passing through the inflow and outflow pipes 292 and 293 is over 20 kPa, the printed circuit board stops the operation of the water-cooled air conditioner by determining that water does not flow due to the freezing in the second heat exchanger 290.

At this point, the printed circuit board transmits a signal to a display (not shown) or a buzzer so as to let the user know that the water does not effectively flow in the second heat exchanger 290.

On the other hand, when the water pressure difference of the waters passing through the inflow and outflow pipes 292 and 293 is less than 20 kPa, the printed circuit board applies electric power to the water-cooled air conditioner to allow the water-cooled air conditioner to normally operate by determining that the water effectively flow.

Meanwhile, a water level detecting unit is provided at a side of the water outflow pipe 293 to determine if the water exists in the second heat exchanger 290 by detecting a water level of the water outflow pipe 293. This water level detecting unit may be formed in a variety of structures.

In the following description, a case where a floater switch 320 is used as the water level detecting unit will be explained. FIG. 7 is an enlarged view of the floater switch 320 mounted in the water-cooled air conditioner.

As shown in FIG. 7, the floater switch 320 is designed to detect the water level using buoyancy. The floater switch 320 is fixed on the water outflow pipe 293 while penetrating from an upper side to a lower side of the outer circumference of the water outflow pipe 293. A floater 322 is provided in the floater switch 320.

That is, the floater 322 is filled with air to vertically move upward and downward depending on the water level. The water outflow pipe 293 is provided at outer and inner sides with nuts 324 so as to be coupled to an upper portion of the floater switch 113.

Therefore, when the floater switch 320 is fixed in a state where it is inserted in the water outflow pipe 293, the floater 322 moves in a vertical direction depending on the water level of the outflow pipe 293.

A switch unit 326 is provided above the floater 322. The switch unit 326 generates an electric signal by contacting an upper end of the floater 322 when the floater 322 moves upward by the buoyancy.

The switch unit 326 is electrically connected to the printed circuit board to transmit the electric signal that is generated when it contacts the floater 322 to the printed circuit board. The printed circuit board operates the compressor 210 when the electric signal is transmitted from the switch unit 326.

The floater switch 320 transmits the electric signal to the printed circuit board when the water level of the water outflow pipe 293 is equal to or greater than a reference water level. That is, in order to realize the heat-exchange between the water and the refrigerant, the water outflow pipe 293 should be filled with water by more than half of the inner space thereof. The reference water level is ½ of an inner diameter of the water outflow pipe 293.

Therefore, the switch unit 326 should be installed at a height that is determined considering a floating position of the floater 322 so that it can properly generate the electric signal depending on the reference water level of the switch unit 326.

In more detail, it is preferable that the floater switch 322 is designed to contact the switch unit 326 when the water outflow pipe 293 is filled with the water by a half of the inner diameter of the outflow pipe 293.

A rubber sealer 328 is provided between the pair of nuts 324. The sealer 328 functions to prevent the water filled in the water outflow pipe 293 from leaking.

Referring again to FIG. 5, a heat exchanger support 298 is provided under the second heat exchanger 290. The heat exchanger support 298 supports the second heat exchanger 290 such that the second heat exchanger 290 is spaced apart from the base pan 209.

That is, the top surface of the heat exchanger support 298 is slightly larger than the bottom surface of the second heat exchanger 290. A rear half of the heat exchanger support 298 is formed to extend and be inclined toward a lower-rear side from the top rear end.

The following will describe an operation of the above-described water-cooled air conditioner with reference to FIGS. 6 and 8 through 12.

FIGS. 8 through 11 are block diagrams illustrating a control method of the water-cooled air conditioner according to an embodiment of the present invention. FIG. 12 is a view illustrating flows of the refrigerant and the water in the heating mode operation of the air conditioner.

In order to operate the water-cooled air conditioner, a sufficient amount of the water flows through the inside of the second heat exchanger 290 so that the heat exchange can be normally realized in the second heat exchanger 290. When the electric power is applied to the air conditioner, the water level detecting unit and the water flow detecting unit detects if a sufficient amount of water exists in the second heat exchanger 290 and if the water flows in the second heat exchanger 290, respectively.

FIG. 8 illustrates a process for operating the air conditioner in accordance with the water exist detection in the second heat exchanger 290 by the floater switch 320 that is the water level detecting unit.

As illustrated in FIG. 8, the control method of the air conditioner using the water level detecting unit includes a water level detecting step S400, a water level comparing step S402, and a driving control step S404.

In the water level detecting step S400, it is determined if the water exists in the second heat exchanger 290 using the floater switch 320. That is, the water level of one of the water inflow pipe 292 and the water outflow pipe 293 that are formed on opposite ends of the second heat exchanger 290.

In the water level comparing step S402, the water level detected in the water level detecting step S400 is compared with a reference water level. As described above, the reference water level is ½ of the inner diameter of one of the water inflow pipe 292 and the water outflow pipe 293.

In the driving control step S404, the compressor 210 is selectively driven in accordance with a difference between the detected water level and the reference water level, thereby selectively operating the air conditioner. That is, when the water level detected by the floater switch 320 is ½ or more of the inner diameter of one of the water inflow pipe 292 and the water outflow pipe 293, the compressor 210 operates.

On the contrary, when the water level detected by the floater switch 320 is less than ½ of the inner diameter of one of the water inflow pipe 292 and the water outflow pipe 293, the compressor 210 does not operate and this state is noted to the user through a display or a buzzer.

FIGS. 9 and 10 are block diagrams illustrating a control method of the compressor and the air conditioner in accordance with the water flow detection by the water flow detecting unit.

A method for controlling the air conditioner by detecting if the water flows in the second heat exchanger 290 using a pressure difference measured at the water inflow pipe 292 and the water outflow pipe 293 will be described with reference to FIG. 9.

As illustrated in FIG. 9, the control method of the air conditioner includes a water pressure detecting step S410 for detecting water pressures using the water pressure sensors 340 installed at the opposite ends of the second heat exchanger 290, a water pressure comparing step S412 for calculating a difference between the water pressures measured in the water pressure detecting step S410 and comparing the difference with a reference water pressure, and a driving control step S414 for controlling the driving of the compressor 210 depending on the comparison result in the pressure comparing step S412.

In the pressure detecting step S410, pressures of the waters flowing along the water inflow and water outflow pipes 292 and 293 are detected by the inflow and outflow pressure sensors 342 and 344.

In the driving control step S414, the compressor 210 stops driving when the pressure difference calculated in the pressure comparing step S412 is equal to or greater than the reference pressure and this state is noted to the user.

At this point, as described above, the reference pressure is 20 kPa. Therefore, when the difference of the pressures of the water detected by the inflow and outflow pressure sensors 342 and 344 is equal to or greater than 20 kPa, the compressor 210 stops driving and this state is noted to the user.

A method for controlling the air conditioner by detecting if the water flows in the second heat exchanger 290 using a water temperature difference measured at the water inflow pipe 292 and the water outflow pipe 293 will be described with reference to FIG. 10.

As illustrated in FIG. 10, the control method of the air conditioner includes a water temperature detecting step S420 for detecting water temperatures using the water temperature sensors 360 installed at the opposite ends of the second heat exchanger 290, a water temperature comparing step S422 for calculating a difference between the water temperatures measured in the water temperature detecting step S420 and comparing the difference between the water temperatures with a reference temperature, and a driving control step S424 for controlling the driving of the compressor 210 depending on the comparison result in the water temperature comparing step S422.

In the water temperature detecting step S410, temperatures of the waters flowing along the water inflow and water outflow pipes 292 and 293 is detected by the inflow and outflow temperature sensors 362 and 364.

In the driving control step S424, the compressor 210 stops driving when the temperature difference calculated in the temperature comparing step S422 is equal to or less than the reference water temperature and this state is noted to the user. That is, as described above, the reference water temperature is 3° C.. Therefore, when the temperature difference of the waters detected by the inflow and outflow temperature sensors 362 and 364 is equal to or greater than 3° C.. The compressor 210 stops driving and this state is noted to the user.

FIG. 11 is a block diagram illustrating a control method of the air conditioner when both of the water level detecting unit and the water flow detecting unit are provided.

A control method includes a water level detecting step S400 for detecting a water level of one of the water inflow and water outflow pipes 292 and 293 using the floater switch 320 provided at the side of the second heat exchanger 290, a water level comparing step S402 for comparing the detected water level with a reference water level, a first driving control step S404 for controlling the driving of the compressor 210 in accordance with the comparison result of the water level comparing step S402, a water flow detecting step S430 for detecting if the water flows in the second heat exchanger 290 using the water flow detecting unit provided at a side of the second heat exchanger 290, and a second driving control step S440 for controlling the compressor 210 depending on the water flow detecting result.

Since each of the steps is already described above, the detailed description thereof will be omitted herein. That is, the steps illustrate in FIG. 11 are a combination of the steps described above.

That is, in the first driving control step S404, the compressor 210 operates when the detected water level is equal to or greater than the reference water level. The reference water level is ½ of the inner diameter of one of the water inflow and water outflow pipes 292 and 293.

Meanwhile, in the water flow detecting step S430, the water flow can be detected using the pressure or temperature difference of waters flowing through the second heat exchanger 290.

Accordingly, the water flow detecting step S430 may include a process for detecting water pressures of the water inflow pipe 292 and the water outflow pipe 293 using the water pressure sensor 340 provided at a side of the second heat exchanger 290 and a process for comparing a difference between the water pressures of the water inflow and water outflow pipes 292 and 293. Since the water pressure detecting process and the pressure comparing process are identical to the water pressure detecting steps S410 and the water pressure comparing steps S412, respectively, the detailed description thereof will be omitted herein.

In addition, the second driving control step S440 is identical to the driving control step S414. That is, when it is determined in the pressure comparing step that the pressure difference is equal to or greater than the reference pressure (20 kPa) in the pressure, the compressor 210 stops driving.

Meanwhile, the water flow detecting step S430 includes a process for detecting temperatures of the waters flowing in the water inflow pipe 292 and the water outflow pipe 292 using the water temperature sensor 360 and a process for comparing a temperature difference between the waters flowing in the water inflow pipe 292 and the water outflow pipe 292 with a reference temperature. At this point, since the water temperature detecting process is identical to the previously described water temperature detecting step S420 and the water temperature comparing process corresponds to the previously described water temperature comparing step S422, a detailed description thereof will be omitted herein.

Since the second driving control step S440 is identical to the driving control step S424. That is, when the temperature difference determined in the temperature comparing process is equal to or less than the reference temperature (3° C.), the compressor 210 stops driving.

As described above, the water level detecting unit and the water flow detecting unit may be simultaneously used together with each other or only one of them may be used. The water flow detection may be done by both of the water temperature detecting method and the water pressure detecting method or by only one of them. That is, although the detecting objects of the water pressure sensor 340 and the water temperature sensor 360 are different from each other but their detecting objects are identical to each other. Therefore, they can be selectively used. In addition, when it is not winter season, only the floater switch 320 may be used in a state where the water pressure sensor 340 and the water temperature sensor 360 are turned off.

The following will describe the refrigerant flow in the outdoor unit in the cooling mode operation of the air conditioner with reference to FIG. 6.

The gas-phase refrigerant is introduced from the outdoor unit 100 into the four-way valve 240 through the third outlet port 248 and is directed to the accumulator 270 through the second outlet port 246 of the four-way valve 240. The gas-phase refrigerant coming out of the accumulator 270 goes into the compressor 210.

The refrigerant is compressed in the compressor 210 and discharged to pass through the oil separator 218. The oil contained in the refrigerant is separator is separated and recovered into the compressor 210 through the oil recovery pipe 219.

That is, as the refrigerant is compressed in the compressor 210, it is mixed with the oil. At this point, since the oil is in a liquid-phase, it can be separated from the refrigerant by the oil separator 218 that is a gas/liquid separator.

Then, the refrigerant passing through the oil separator 218 is introduced into the four-way valve 240 through the inlet port 242 and is then directed to the second heat exchanger 290 through the first outlet port 244 of the four-way valve 240.

The discharged refrigerant is introduced into the second heat exchanger 290 through the refrigerant inflow pipe 294 and heat-exchanged with the water introduced from the cooling tower 80 into the second heat exchanger 290 through the water inflow pipe 292, thereby being converted into the liquid-phase refrigerant. Then, this liquid-phase refrigerant is directed to the over-cooler 260 to be further cooled.

At the same time, the water is wormed during the heat exchange with the refrigerant in the second heat exchanger 290 is discharged out of the second heat exchanger 290 through the water outflow pipe 293 and is then introduced into the cooling tower 80 through the water outflow passage 202″.

The water introduced into the cooling tower 80 is introduced again into the second heater exchanger 290 through the water inflow passage 202′. This process is continuously repeated.

Meanwhile, the refrigerant passing through the over-cooler 260 further passes through a drier where the moisture contained in the refrigerant is removed and is then introduced into the indoor unit 100. Then, the refrigerant is pressure-reduced by the expansion valve and heat-exchanged in the first heat exchanger 120 (see FIG. 2). At this point, since the first heat exchanger 120 functions as an evaporator, the refrigerant is converted into a low pressure gas-phase through the heat exchange.

The refrigerant heat-exchanged while passing through the first heat exchanger 120 flows along the common gas-phase pipe 134 and is then introduced into the accumulator 270 via the four-way valve 240.

The accumulator 270 filters off the liquid-phase refrigerant so that only the gas-phase refrigerant can be fed to the compressor 210. By the above-described series of processes, one cooling cycle is completed.

The following will describe the flow of the refrigerant in the heating mode operation of the water-cooled air conditioner with reference to FIGS. 2 and 13. The refrigerant compressed by the compressor 210 is introduced into the outdoor unit 200 through the outdoor liquid-phase pipe 262 via the indoor unit 100. Then, the refrigerant is heat-exchanged with the water while passing through the second heat exchanger 290.

Then, the heat exchanged refrigerant is directed into the accumulator 270 through the first and second outlet ports 244 and 246 of the four-way valve 240. In the accumulator 270, the liquid-phase refrigerant is filtered off and only the gas-phase refrigerant is introduced into the compressor 210, thereby completing the heating cycle.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

For example, although the water and the refrigerant are heat-exchanged with each other in the second heat exchanger 290, the present invention is not limited this configuration. That is, instead of the water, other liquids may be used. 

1. A water-cooled air conditioner comprising: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; and a water detecting unit for detecting if the water exists in the heat exchanger, the water detecting unit being provided at a side of one of the water inflow and outflow pipes.
 2. The water-cooled air conditioner according to claim 1, wherein the water detecting unit is a floater switch for detecting if the water exists by measuring a water level of one of the water inflow and outflow pipes.
 3. A water-cooled air conditioner comprising: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; and a water flow detecting unit for detecting if the water flows in the heat exchanger, the water flow detecting unit being provided at a side of one of the water inflow and outflow pipes.
 4. The water-cooled air conditioner according to claim 3, wherein the water flow detecting unit includes water pressure sensors for detecting water pressures of the water inflow and outflow pipes and determining if the water flows using a pressure difference between the water pressures detected, the water pressure sensors being installed at sides of the water inflow and outflow pipes, respectively.
 5. The water-cooled air conditioner according to claim 4, wherein the water pressure sensors include: an inflow pressure sensor that is installed on the water inflow pipe to detect the water pressure of the water inflow pipe; and an outflow pressure sensor that is installed on the water outflow pipe to detect the water pressure of the water outflow pipe.
 6. The water-cooled air conditioner according to claim 3, wherein the water flow detecting unit includes water temperature sensors for detecting water temperatures of the water inflow and outflow pipes and determining if the water flows using a temperature difference between the water temperatures detected, the water temperature sensors being installed at sides of the water inflow and outflow pipes, respectively.
 7. The water-cooled air conditioner according to claim 6, wherein the water temperature sensors include: an inflow temperature for detecting the water temperature of the water inflow pipe; and an outflow temperature sensor for detecting the water temperature of the water outflow pipe.
 8. A water-cooled air conditioner comprising: a compressor for compressing refrigerant; a plate-shaped heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with water; water inflow and outflow pipes for guiding inflow and outflow of the water, the water inflow and outflow pipes being provided in the heat exchanger; a water detecting unit for detecting if the water exists in the heat exchanger, the water detecting unit being provided at a side of one of the water inflow and outflow pipes; and a water flow detecting unit for detecting if the water flows in the heat exchanger, the water flow detecting unit being provided at a side of one of the water inflow and outflow pipes.
 9. The water-cooled air conditioner according to claim 8, wherein the water detecting unit is a floater switch for detecting if the water exists by measuring a water level of one of the water inflow and outflow pipes.
 10. The water-cooled air conditioner according to claim 8, wherein the water flow detecting unit includes water pressure sensors for detecting water pressures of the water inflow and outflow pipes and determining if the water flows using a pressure difference between the water pressures detected, the water pressure sensors being installed at sides of the water inflow and outflow pipes, respectively.
 11. The water-cooled air conditioner according to claim 10, wherein the water pressure sensors include: an inflow pressure sensor that is installed on the water inflow pipe to detect the water pressure of the water inflow pipe; and an outflow pressure sensor that is installed on the water outflow pipe to detect the water pressure of the water outflow pipe.
 12. The water-cooled air conditioner according to claim 8, wherein the water flow detecting unit includes water temperature sensors for detecting water temperatures of the water inflow and outflow pipes and determining if the water flows using a temperature difference between the water temperatures detected, the water temperature sensors being installed at sides of the water inflow and outflow pipes, respectively.
 13. The water-cooled air conditioner according to claim 12, wherein the water temperature sensors include: an inflow temperature for detecting the water temperature of the water inflow pipe; and an outflow temperature sensor for detecting the water temperature of the water outflow pipe.
 14. The water-cooled air conditioner according to claim 8, wherein the water flow detecting unit includes: water pressure sensors for detecting water pressures of the water inflow and outflow pipes and determining if the water flows using a pressure difference between the water pressures detected, the water pressure sensors being installed at sides of the water inflow and outflow pipes, respectively; and water temperature sensors for detecting water temperatures of the water inflow and outflow pipes and determining if the water flows using a temperature difference between the water temperatures detected, the water temperature sensors being installed at sides of the water inflow and outflow pipes, respectively.
 15. The water-cooled air conditioner according to claim 14, wherein the water pressure sensors include: an inflow pressure sensor that is installed on the water inflow pipe to detect the water pressure of the water inflow pipe; and an outflow pressure sensor that is installed on the water outflow pipe to detect the water pressure of the water outflow pipe.
 16. The water-cooled air conditioner according to claim 14, wherein the water temperature sensors include: an inflow temperature for detecting the water temperature of the water inflow pipe; and an outflow temperature sensor for detecting the water temperature of the water outflow pipe.
 17. A method of controlling a water-cooled air conditioner, comprising: detecting a water level of one of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing the water level detected with a reference water level; and controlling a driving of a compressor depending on a comparison result between the detected water level and the reference water level.
 18. The method according to claim 17, wherein the compressor is controlled to drive when the detected water level is equal to or greater than the reference water level.
 19. The method according to claim 18, wherein the reference water level is ½ of an inner diameter of one of the water inflow and outflow pipes.
 20. A method of controlling a water-cooled air conditioner, comprising: detecting water pressures of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing a pressure difference between the water pressures detected with a reference water pressure; and controlling a driving of a compressor depending on a comparison result between the pressure difference and the reference water pressure.
 21. The method according to claim 20, wherein the compressor is controlled to stop driving when the pressure difference is equal to or greater than the reference water pressure.
 22. The method according to claim 21, wherein the reference water pressure is 20 kPa.
 23. A method of controlling a water-cooled air conditioner, comprising: detecting water temperatures of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing a temperature difference between the water temperatures detected with a reference water temperature; and controlling a driving of a compressor depending on a comparison result between the temperature difference and the reference water temperature.
 24. The method according to claim 23, wherein the compressor is controlled to stop driving when the temperature difference is equal to or less than the reference water temperature.
 25. The method according to claim 23, wherein the reference water temperature is 3° C.
 26. A method of controlling a water-cooled air conditioner, comprising: detecting a water level of one of water inflow and outflow pipes that are provided at a side of a heat exchanger to guide inflow and outflow of the water; comparing the water level detected with a reference water level; controlling a driving of a compressor depending on a comparison result between the detected water level and the reference water level; detecting if the water flows in the heat exchanger using a water flow detecting unit provided at a side of the heat exchanger; and further controlling the driving of the compressor depending on whether the water flows or not.
 27. The method according to claim 26, wherein the compressor is controlled to drive when the detected water level is equal to or greater than the reference water level.
 28. The method according to claim 27, wherein the reference water level is ½ of an inner diameter of one of the water inflow and outflow pipes.
 29. The method according to claim 26, wherein the detecting if the water flows comprises: detecting water pressures of the water inflow and outflow pipes; and comparing a pressure difference between the water pressures detected with a reference water pressure.
 30. The method according to claim 29, wherein the compressor is controlled to stop driving when the pressure difference is equal to or greater than the reference water pressure.
 31. The method according to claim 30, wherein the reference water pressure is 20 kPa.
 32. The method of claim 26, wherein the detecting if the water flows comprises: detecting water temperatures of the water inflow and outflow pipes; and comparing a temperature difference between the water temperatures detected with a reference water temperature.
 33. The method according to claim 32, wherein the compressor is controlled to stop driving when the temperature difference is equal to or less than the reference water temperature.
 34. The method according to claim 33, wherein the reference water temperature is 3° C. 